CFD Convective Flow Simulation of the Varying Properties of CO(2)-H(2)O Mixtures in Geothermal Systems

Numerical simulation of a geothermal reservoir, modelled as a bottom-heated square box, filled with water-CO(2) mixture is presented in this work. Furthermore, results for two limiting cases of a reservoir filled with either pure water or CO(2) are presented. Effects of different parameters including CO(2) concentration as well as reservoir pressure and temperature on the overall performance of the system are investigated. It has been noted that, with a fixed reservoir pressure and temperature, any increase in CO(2) concentration leads to better performance, that is, stronger convection and higher heat transfer rates. With a fixed CO(2) concentration, however, the reservoir pressure and temperature can significantly affect the overall heat transfer and flow rate from the reservoir. Details of such variations are documented and discussed in the present paper.